Obstetrical forceps



1956 w. B. SHUTE OBSTETRICAL FORCEPS 2 Sheets-Sheet 1 Filed Sept. 20 1954 lm/em-rog W LL ce 6. SHu -r 5 M 'T'TO QNEyS Aug. 7, 1956 w H T 2,757,673

OBSTETRICAL Foacss Filed Sept. 20,1954 z'snee ts-sneez 2 INVENTOQ.

WALLACE- 6. 5Hu-rE TT QNEY6 United States I OBSTETRICAL FORCEPS Wallace B. Shute, Ottawa, Ontario, Canada Application September 20, 1954, Serial No. 457,149

Claims priority, application Canada May 25 1954 Claims. (Cl. 128--323) This invention relates to obstetrical forceps and in particular to obstetrical forceps having a novel link means between the two cooperating members.

Obstetrical forceps in common use today are mainly of the scissors type. In other words they consist of two members which are pivotally connected together at a point of intersection and the distance between the blades and the pressure exerted by them is controlled by the distance between the handles and the pressure exerted on them by the physician. It will readily be seen that this construction gives rise to a very serious disadvantage. If insufficient pressure is exerted there is a danger of the blades slipping and bearing on a surface for which they are not designed with a resulting injury to the child. If too much pressure is exerted in an attempt to avoid slipping the child may be injured.

The scissors type of construction also has the disadvantage that the blades are not parallel and move angularly with respect to one another and unless great care is taken greater pressure is exerted by the sections of the blades nearest the pivot than by the tips of the blades, with consequent injury to the child.

With these disadvantages in view the present invention was evolved which has as its principal object the provision of obstetrical forceps, the blades of which can be adjusted to remain in a constant fixed relationship to one another.

It is a further object to provide a pair of obstetrical forceps, the blades of which can be adjusted to various relative positions while remaining substantially parallel.

It is a further object of this invention to provide a pair of obstetrical forceps which can be adjusted so that the minimum pressure exerted between the blades can be controlled to avoid slipping of the blades and so that the maximum pressure can likewise be controlled and so avoid bruising and other injury.

The obstetrical forceps which embody the above objects comprise a pair of members each having a handle at one end, a blade at the other end and a shaft therebetween. In each shaft there is a recess which, when the blades are in their co-operative position, opens towards the recess in the other shaft. Means including a block having a pair of legs threaded through a pair of holes in the block is mounted in one recess and the legs extend into the recess in the other member and engage therewith to hold the two members in fixed relationship to one another.

By way of illustration an embodiment of the invention will be described in detail with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a pair of obstetrical forceps embodying the invention,

Figure 2 is a detail view of the joining mechanism in cross-section,

Figure 3 is another view of Figure 2, and

Figure 4 is a further detailed view of a part of Figure 2.

Referring now to Figure 1 it will be seen that the obstetrical forceps which embody the present invention Patented Aug. 7, 1955 comprise two members A and B having handles 10, blades 11 and shafts 12 therebetween. A mechanism indicated generally at J joins the two members A and B and holds them in a substantially fixed relationship one to the other.

In Figure 2 a portion of the shafts 12 is shown in cross-section illustrating two recesses 13 and 14 which lie in shafts 12 of members A and B respectively. Recess 14 which lies in shaft 12 of member B comprises a main cavity 15 which is partly closed by a projection 16 which extends across a part of the cavity 15 in a direction parallel to the shaft 12. On the side of main cavity 15 remote from the blade 11 is a second cavity 17 separated from cavity 15 by web 18. Cavity 17 has a bottom surface which curves from the edge 19 of shaft 12 downwardly to form a bearing surface 20 adjacent web 18. The function of this recess will be further described below.

In shaft 12 of member A lies recess 21 which is of substantially rectangular shape and which extends completely through shaft 12. A portion 22 of shaft 12 has not been cut away and projects into the rectangular cavity to partially enclose it on the side of shaft 12 remote from the adjacent member B. In the recess is mounted a'block 23 by a pivot 24 near one corner thereof. Two internally threaded holes 25 and 26 are provided in block 23' and through these holes are threaded legs 27 and 28. Legs 27 and 28 are threaded throughout their length and are provided at one end with knurled knobs 29 and 30 and at the other with means to engage recess 14 in member B. The means to engage recess 14 comprise a foot or projection at right angles to leg 27 and mounted rotatably thereon to lie beneath projection 16 and bear thereagainst. Leg 28 is formed with a bearing surface at its end and is adapted to bear against surface 20 in cavity 17.

In a corner of block 23 other than the corner having the pivot 24 is a catch 31. This can best be seen from Figure 4 which shows a section along line 4-4 of Fig ure 2. A cavity 32 is provided in block 23 which extends partly through the block. A cylindrical member 34 lies in cavity 32 urged outwardly by spring 33. A hole 35 to receive cylinder 34 is provided in face 36 of recess 21. A smaller hole 37 extends from the external face of shaft 12 to the bottom of hole 35 and carries a shaft 38 with a disc 39 secured to the end thereof in hole 35. A convenient knob 40 is provided on the exposed end. The hole 35 is located in face 36 so that when cylinder 34 is seated therein legs 27 and 28 are at right angles to shaft 12. When knob 40 is pushed until the face 41 of cylinder 34 is flush with face 36 of the recess the block and legs can be pivoted about point 24 to occupy the position shown in Figure 3. The contact of cylinder 34 urged outwardly by spring 33 provides sufiicient friction between face 41 of cylinder 34 and face 36 of recess 21 to hold block 23 and legs 27 and 28 against accidental displacement.

A consideration of Figure 2 will make it evident that as pressure is applied to the handles to force them together, leg 28 with leg 27 will hold the members A and B immovable. By turning the knurled knobs 29 and 30 the distance between members A and B can be varied as can their angular relationship. In any position the maximum and minimum pressure exerted between the blades is controlled by the legs 27 and 28 and thus can be very accurately adjusted.

I claim:

1. A pair of obstetrical forceps comprising two members each having a handle at one end and a blade at the other with a shaft therebetween, each member having a recess in its shaft, the recesses opening towards one another when the members are in a co-operative position, a pair of legs extending from one recess into the other recess to hold the two members in fixed relationship to one another.

2. A pair of obstetrical forceps comprising two members each having a handle at one end and a blade at the other with a shaft therebetween, each member having a recess in its shaft, the recesses opening towards one another when the members are in a co-operative position, ablock in one of said recesses, a pair of legs adjustably mounted in said block extending into and engaging the other reoem to hold the two members in fixed relationship to one another.

3. A pair of obstetrical forceps comprising two members each having a handle at one end and a blade at the other with a shaft therebetween, each member having a recess in its shaft, the recesses opening towards one another when said members are in a co-operating position, a block pivotally mounted in one recess in one member and having threaded holes therethrough, a leg threaded through each hole and extending towards and into the recess in the othermember and engaging a notch therein to hold the two members in fixed relationship one to the other.

4. A pair of obstetrical forceps comprising two members each having a handle at one end and a blade at the other with a shaft therebetween, each member having a recess in its shaft, the recesses facing each other when the members are in a co-operative position, a block pivotally mounted by one corner in the recess of one member, said block having two parallel holes therethrough, a leg threaded through each hole and extending into the recess of the other member, one of the legs bearing against a surface in the recess of the other member to keep the two members apart, the second leg having a projection thereon to engage a catch in the recess at said other member to prevent the further separation of the members thus holding the two members in fixed relationship to one another.

5. A pair of obstetrical forceps comprising two members each having a handle at one end and a blade at the other with a shaft therebetween, each member having a recess in its shaft, the recesses opening towards one another when the members are in a oo-operative position, a block pivotally mounted by one corner in the recess of one member, said block having two parallel holes therethrough provided with internal threads, a leg threaded through each hole, one leg having an end bearing surface and the other having a projection at right angles to the leg, the other recess in the other member having a pocket having a bottom bearing surface to support the leg having the end bearing surface and a projection to engage the projection on the other leg, knobs on the ends of the legs remote from the recess engaging ends to enable them to be turned and threaded into or out of the holes in the block to vary the length between the memben, the legs holding the two members in adjustable, fixed relationship to one another.

References Cited in the file of this patent UNITED STATES PATENTS 1,614,679 Odell Jan. 18, 1927 

